1. The Field of the Invention
The field of the invention relates to the purification of oils and more particularly the elimination of contaminant polychlorinated bi-phenyls (hereinafter "PCB's") from hydrocarbonaceous oils by the treatment of such oils with liquid sodium. Accordingly the general objects of the present invention are to provide a novel and improved method of such character.
2. Description of the Prior Art
The background art of the invention reveals various attempts at elimination and destruction of PCB's, highly toxic environmental polutants, from oil, and particularly transformer oil. Reference is made for this purpose to the Naphthalide Process of Goodyear Company, the Acutrex Process of Sohio Company, the Microfine Process and the efforts of one Robert Layman and Lynwood Kemp, employees or consultants to Life Enterprises, Inc. and The Chemical Decontamination Corporation, both Pennsylvania Corporations, in addition to others not presently identifiable by your applicant. These methods are generally characterized by reactions which attempt to strip away chlorine from the aromatic ring structure of the bi-phenyl leaving, inter alia, a non-chlorinated bi-phenyl, benzene, chloro-benzene and sodium chloride, some of which are themselves environmentally harmful. In addition, previous inventions have proven incapable of, or uneconomical in, reducing the level of PCB's or by creating other toxic contaminants. One of the basic problems encountered, which the present invention solves, has been the uncontrolled formation of undesirable free radicals occasioned by the presence of various addition products, including sodium, and a consequent polymerization or combination of such radicals into environmentally harmful products remaining in the oil. The objective of the present invention is to reduce PCB levels to below two (2) parts per million (hereinafter "ppm") as preferred and required by the Environmental Protection Agency (hereinafter "EPA") and without forming other contaminants before the oil is re-cycled for use as, for example, in transformers. A further object is to reduce large polymer by-products possible in the reaction simultaneously therewith by controlled hydrogenation of free radicals of bi-phenyl and other remnants of the destructive reaction process. Within recent date in the United States, at least fourteen million (14,000,000) metric tons of unuseable, nondisposable transformer oil containing PCB's remained untreated. As has been well-publicized the mere storage of oil-containing PCB's is in itself a severe, continuing threat to the environment and constitutes an uneconomical sequestration of capital by compelling the maintenance of such oils in static inventory and in special storage facilities.
The method disclosed in this application provides a cheap, rapid, indeed portable, means for reducing to acceptable levels, and at times in fact eliminating altogether, PCB's in oils.